Stringed musical instrument and method of sound amplification



June 5, 1934. T. A. GAST 1,961,900

STRINGED MUSICAL INSTRUMENT AND METHOD OF SOUND AMPLIFICATION File'd NOV. 1931 2 Sheets-Sheet l MCdA M c3 07 T.- A. GAST 1,961,900

STRINGED MUSICAL INSTRUMENT AND METHOD OF SOUND AMPLIFICATION June 5, 1934.

Filed Nov. 6. 1 2 Sheets-Sheet NN NW RN QWN Q w QNNN QNN Patented June 1934 UNITED STATES PATENT OFFICE STRINGED MUSICAL INSTRUMENT AND METHOD OF SOUND AMPLIFICATION of Illinois Application November 16, 1931, Serial No. 575,186

19 Claims.

5 5 such as the string of a musical instrument, by

transmission positively through mechanical means of sound vibration to a resonating member or sound board, and as a corollary of that object to utilize also concurrently the air column vibration found, for example, in box type musical instruments, such as the guitar, violin and others.

Another object consists in the provision of means to effect the practice of the method or process.

Other-objects relate to the details and to the arrangements and sub-arrangements of parts hereinafter described and set forth.

I have discovered that the tone and sound Volume produced by a vibrating element, such as the string of a musical instrument, may be increased and imparted by direct transmission of that vibration through mechanical means to a resonating member or sounding board.

I have illustrated in the accompanying drawings, two embodiments of my invention as applied to a guitar.

In the accompanying drawings, Fig. 1 is a plan view of a guitar having one embodiment of my invention applied thereto;

Fig. 2 is a vertical section along the line 2-2 of Fig. 1 drawn to an enlarged scale;

Fig. 3 is a transverse vertical section along the line 3-3 of Fig. 1, also drawn to an enlarged scale;

Fig. 4 is a view similar to Fig. 2 illustrating a modified form of my invention;

Fig. 5 is a vertical transverse section along the line 5-5 of Fig. 4; and

Fig. 6 is an end view from the plane of 6-6 in Fig. 4 on a slightly diminished scale.

Like numerals refer to like elements throughout the drawings in which 10 indicates generally a guitar comprising the usual neck 11, tuning members 12, strings 13, whose tension may be increased or diminished by actuation of the tuning members in well known manner, a body or casing 14, bridge 15, and tail piece 16. The casing 14 comprises the top 14a, bottom 14b, and side walls 140. In the form shown, the bottom member 141) is of a concave-convex construction, although I do not wish to be restricted to such form in the practice of my invention.

The strings 13 extend from the tuning members 12 over the bridge 15 and into engagement with one end of the tailpiece 16. v

It is my understanding that in the conventional musical instrument of this type, the top 14a and bottom 141; are relatively thin and function as resonating members or sounding boards, the vibration of a string or strings when struck being transmitted, in the first instance, to the top 14a mainly or wholly through the bridge 15. Such vibration is then, as I understand it, transmitted by vibrating air columns in the casing to the bottom resonator 14b, which amplifies and imparts resonance to the tone thus obtained. The top 14a is provided with an aperture or opening 14m beneath the strings in conventionally constructed instruments.

In the embodiment illustrated, the tail-piece instead of being attached to the end of the instrument, as in present day devices, is pivotally attached to the upper end of an elbow or connecting arm 18 at and spaced from the end of the casing 14. At its other end, the arm 18 is provided with an angularly and rearwardly extended lever 19, preferably rigidly secured to the arm 18, as illustrated in Fig. 2, for example.

Intermediate the ends of the arm 18 is provided a fulcruminember 20, having an outwardly projecting rib 20a and angularly disposed base portions 20b resting against the end of the instru- -ment. In the form illustrated, this fulcrum may be adjusted to engage any one of a series of notches 18a in the arm 18 to vary the leverage transmitted by the arm 18 and lever 19. I find it desirable, in some instances, at least, after determination of the most desirable location of the fulcrum 20 to anchor or fix it in such position to prevent tampering or accidental displacement thereof. Similarly, a plurality of holes 18b are provided near the upper end of the arm 18 for adjustment of the position of the pin 16' which engages the looped end of the tail-piece 16.

There is provided a reinforcing piece or strip 22 inside the casing 14 extending from top to bottom thereof and serving to brace the end of the guitar adjacent the position of the fulcrum member 20. The side wall 140 and the brace 22 are apertured as indicated by numeral 24, and the lever 19 extends therethrough to the interior of the casing 14 preferably out of contact with the sides of the opening 24. Adjacent the inner end of the lever 19 is provided a bridge member 26 resting upon the bottom 14b. The inner end of the lever 19 rests upon this bridge 26, the purpose being efliciently to transmit oscillations of the lever through the bridge 26 to the bottom 14b.

It will be apparent that the length of the lever 19 and the location of the bridge 26 may be varied. I have found it advisable, at least with each different type and size of instrument to which my invention is applied, to determine by test and trial the best proportions of the lever 19 and arm 18, also the best relative position of the fulcrum member 20, and the best or most desirable location for the bridge 26.

In the practice of my method in the use of the device illustrated in Figs. 1 to 3 of the drawings, the vibration of one or more of the strings when struck will, in the first instance, be transmitted through the bridge 15 to the top 14a, setting up a vibration therein which, according to my understanding, is transmitted in the present day instruments through air columns in the casing to the bottom, which also functions as a resonator or sounding board. With my invention, the vibration of the string or strings at the same time is transmitted positively and directly through the tail-piece 16, arm 18, and lever 19 to the bottom or resonator 141) by means of the interposed bridge member 26. By proper proportioning of the parts, as suggested above, and by proper location of the bridge 26 for the production of the best or desired results, the tone produced is amplified and the resonance of the instrument apparently increased due, in my opinion or understanding, to the intensifying or amplifying of the vibrations of the bottom resonator 14!), by the oscillatory lever 19, and presumably (when properly adjusted and arranged) in synchronism or in harmony with the air column vibrations in the casing.

In Figs. 4 to 6 I have illustrated a modification in which a plane bottom 114i) is illustrated, although I do not wish to be restricted to that particular form. A bridge 126 is mounted in the selected position on the inner surface of the bottom 11412 and provided with an aperture 126a, through which extends the lever 119. This lever is of bell crank construction, and adjacent its apex is mounted upon a fulcrum plate 130 extending across the opening 24 of the end wall of the guitar. The other arm 119a of the lever 119 is extended vertically upward and pivotally engages at 11% the arm 118 mounted upon the fulcrum 120. In other respects, the construction is the same as that illustrated in Figs. 1 to 3. The main difference resides in the fact that the lever construction and arrangement is such that the inner end of lever 119 exerts an upward thrust upon the bridge 126, and a pull or increased tension upon any or all of the strings, and tends to pull the bottom 1141b upwardly rather than to press it downwardly, as in the form of Figs. 1 to 3. The resultant effect and the operation is generally similar.

It will be apparent that my invention, as described and illustrated, is susceptible of modification and departure from the specific forms illustrated and described, and consequently I do not wish to be restricted thereto, but refer to the appended claims, properly interpreted with respect to prior art, as defining the scope of my invention.

What I claim is:

1. A stringed musical instrument comprising in combination, a tailpiece, a supporting frame, a string carried thereby and secured to said tailpiece, a resonating member and means operatively connecting said tailpiece and said member whereby vibration of said string will be positively transmitted through said means to said member.

2. A stringed musical instrument comprising in combination, a supporting frame including spaced resonating members, a string overlying and adjacent one of said members, and means including a tailpiece operatively connecting said string, and the other of said resonating members whereby vibration of said string will be positively transmitted through said means to said second resonating member.

3. A stringed musical instrument comprising in combination, a supporting frame including spaced resonating members, a string overlying and adjacent one of said members, and means operatively connecting said string, and the other of said resonating members whereby vibration of said string will be positively transmitted through said means to said second resonating member, said means including an oscillatory lever.

4. A stringed musical instrument comprising in combination, a supporting frame including spaced resonating members, a string overlying and adjacent one of said members, and means operatively connecting said string, and the other of said resonating members whereby vibration of said string will be positively transmitted through said means to said second resonating member, said means including a fulcrum and an oscillatory lever.

5. A stringed musical instrument comprising in combination, a supporting frame including spaced resonating members, a string overlying and adjacent one of said members, and means operatively connecting said string, and the other of said resonating members whereby vibration of said string will be positively transmitted through said means to said second resonating member, said means including a fulcrum and an oscillatory lever, said fulcrum being adjustable as to position.

6. A stringed musical instrument comprising in combination, a supporting frame including spaced resonating members, a string overlying and adjacent one of said members, and means operatively connecting said string, and the other of said resonating members whereby vibration of said string will be positively transmitted through said means to said second resonating member, said means including an oscillatory lever, and a bridge opera tively associated with said resonating member and actuated by said lever during vibration of said string.

7. A stringed musical instrument comprising in combination, a supporting frame including spaced resonating members, a string overlying and adjacent one of said members, and means operatively connecting said string, and the other of said resonating members whereby vibration of said string will be positively transmitted through said means to said second resonating member, said means including an oscillatory lever, and an arm operatively interposed between said string and said lever.

8. A stringed musical instrument comprising in combination, a supporting frame including spaced resonating members, a string overlying and adjacent one of said members, and means operatively connecting said string, and the other of said resonating members whereby vibration of said string will be positively transmitted through said means to said second resonating member, said means including an oscillatory lever, a fulcrum, and an arm operatively interposed between said string and said lever, said arm co-acting with said fulcrum.

9. A stringed musical instrument comprising in combination, a frame comprising a top and a bottom spaced from said top, a string above and spaced from said top, a tail-piece engaging one end of said string, means including an oscillating lever contacting said bottom, and means operatively connecting said tail-piece and said lever whereby vibrations of said string will be directly transmitted to said lever and thereby to said bottom.

10. A stringed musical instrument comprising in combination, a frame comprising a top and a bottom spaced therefrom, a bridge mounted upon said top, a tail-piece, a string located above said top and upon said bridge, said string engaging said tail-piece, means including an oscillatory lever contacting said bottom, and means operatively connecting said tail-piece and said lever whereby vibrations of said string will be directly transmitted to said lever and thereby to said bottom.

11. A stringed musical instrument comprising in combination, a frame comprising a top and a bottom spaced from said top, a string above and spaced from said top, a tail-piece engaging one end of said string, means including an oscillating lever contacting said bottom, an arm operatively connecting said lever and said tail-piece, and a fulcrum for said arm whereby vibrations of said string will be transmitted to said lever and thereby to said bottom.

12. A stringed musical instrument comprising in combination, a frame, a box-like construction comprising a top, a bottom and an apertured side wall, a string located adjacent said top, a tailpiece engaging one end of said string, means including an oscillatory lever extending through the aperture in said side wall and contacting said bottom, and means operatively connecting said tailpiece and said lever.

13. A stringed musical instrument comprising in combination, a frame comprising a top and a bottom, a tail-piece, a string located adjacent said top and engaging said tail-piece, means including a bell crank having one arm constituting an oscillatory lever contacting said bottom, the other arm of said bell crank being angularly extended with respect to said lever arm, and an elbow operatively connecting said angularly extending bell crank arm and said tail-piece whereby vibrations of said string will be transmitted to said lever and thereby to said bottom.

14. In combination, a supporting frame including spaced resonating members, a string overlying and adjacent one of said members, means receiving the axial vibrations of said string, and a second means actuated thereby to oscillate, said second means being vibratorily associated with one of said resonating members.

15. In combination, a supporting frame including spaced resonating members, a string overlying and adjacent one of said members, and means operatively attached to said string to receive the axial vibrations thereof, said means being vibratorily associated with the other of said resonating members, thereby to vibrate the same.

16. The method of amplifying sound resulting from vibration of a string, consisting in transmitting lateral vibrations of said string pneumatically to a resonating member, and converting longitudinal vibrations of said string into transverse vibrations and in transmitting the latter to said resonating member.

17. The method of amplifying sound consisting in transmitting lateral vibrations of a string positively to a resonating member, transmitting said vibrations from said resonating member to a second spaced resonating member, and converting axial vibrations of said string into transverse vibrations, and transmitting the same to said second resonating member independently of said first resonating member.

18. The method of amplifying sound consisting in transmitting lateral Vibrations of a string to a resonating member, transmitting said vibrations from said resonating member pneumatically to a second spaced resonating member and converting axial vibrations of said string into transverse vibrations, and transmitting the same to said second resonating member independently of said first resonating member.

19. The method of amplifying sound consisting in transmitting lateral vibrations of a string positively to a resonating member, transmitting said vibrations from said resonating member pneumatically to a second spaced resonating member and converting axial vibrations of said string into transverse vibrations, and transmitting the same to one of said resonating members independently of the other of said members.

THEODORE A. GAST. 

